most problems are caused by the following situations. check for these items first when starting your troubleshooting:

    1 faulty or loose cables. look for loose or obviously faulty connections. if they appear to be ok, make sure the connections are snug. if that does not correct the problem, try a different cable.

    2 non-standard cables. non-standard and miswired cables may cause network collisions and other network problems, and can seriously impair network performance. use a new correctly-wired cable or compare your cable to the cable in appendix b, “switch ports and network cables” for pinouts and correct cable wiring. a category 5 cable tester is a recommended tool for every 100base-t and 1000base-t network installation.

    3 invalid network topologies. it is important to make sure you have a valid network topology. common topology faults include excessive cable length and excessive repeater delays between end nodes. if you have network problems after recent changes to the network, change back to the previous topology. if you no longer experience the problems, the new topology is probably at fault.

    in addition, you should make sure that your network topology contains no data path loops. between any two end nodes, there should be only one active cabling path at any time. data path loops will cause broadcast storms that will severely impact your network performance.

    with your procurve 8100fl switches, if you wish to build redundant paths between important nodes in your network to provide some fault tolerance, you should enable spanning tree protocol support on the switch. this ensures that only one of the redundant paths is active at any time,thus avoiding data path loops.

    procurve 8100fl switches also support link aggregation, which allows multiple network cables to be used for a single network connection without causing a data path loop.

    for more information on enabling spanning tree and link aggregation, see the management and configuration guide on the documentation cd-rom that came with your switch.

    4 check the port configuration. a port on your procurve switch 8100fl may not be operating as you expect because it has been put into a “blocking” state by spanning tree, or lacp (automatic link aggregation). (note that the normal operation of the spanning tree and lacp features may put the port in a blocking state.) or, the port just may have been configured as disabled through software.

    check the port’s configuration and verify that there is not an improper or undesired configuration of any of the switch features that may be affecting the port. see the management and configuration guide that is on the documentation cd-rom that came with your switch for more information.

    for more information on possible network problems and their solutions, refer to the technical note “troubleshooting lan performance and intermittent connectivity problems”, which can be found on the procurve networking web site, http://www.procurve.com, in the information library section.